Periodontal disease is a pathogenic infection of the gums which is common among all humans and animals. The disease provides a major pathway to the loss of teeth and oral bone throughout every society, leading to extreme personal discomfort among the afflicted. Given the prevalence of the disease and related costs, effective treatments of the disease and prevention strategies are continually being pursued.
A major contributor to periodontal disease concerns the oral environment. The oral environment provides a warm moist cavity that is full of nutrients, making it an excellent location to incubate microbes. It is not surprising, therefore, that pathogens readily ingress into periodontal pockets where the infection occurs. In the milder forms of periodontal disease—commonly referred to as gingivitis—the gums redden, swell and bleed easily. Gingivitis is limited to the soft tissue surrounding the tooth and does not typically result in bone loss. This stage of the disease is reversible with treatment and proper oral care. On the other hand, uncontrolled or rampant periodontal infection leads to advanced stages of the disease called periodontitis. Left untreated, periodontitis causes progressive bone loss around teeth that ultimately results in the teeth becoming loose from their sockets. There are few if any characteristic stages of progression, as the driving actions underlying the disease are the same—e.g., accumulation of bacteria at the gum line leading to the formation of dental plaque. A specific treatment of the disease depends primarily on the extent of the disease—e.g., the extent of the infection or the formation of plaque.
Some common characteristics of the disease are as follows. First, there occurs an accumulation of bacteria at the gum line that forms bacterial or dental plaque. Bacterial plaque later calcifies to form calculus, which can exist both above and below the gum line. At the same time, there occurs a sustained dramatic change in the normal micro flora existing below the gum line in the region between the gum and tooth—typically referred to as the gingival margin. Disease causing microbes find a safe home in the gingival margin, where they are safe from the tongue and major saliva pathways, thereby upsetting the balance of micro flora. The rogue microbes begin to emit enzymes that destroy the connective tissue between teeth and gums which creates a “periodontal pocket.” Because the mouth acts as an incubator with a good supply of nutrition, microbes flourish in the periodontal pockets. Dentists use a tool called a periodontal probe to measure pocket depths of individual patients. This provides a measure of the depth the rogue microbes have eaten the connective tissue away. The deeper the periodontal pocket goes, the more difficult it is to treat. When the pockets are near the surface (say about less than 3 mm) the pocket can in some cases be treated with a sulcular disinfection regime as disclosed in commonly owned U.S. patent application Ser. No. 11/382,586. An appropriate disinfection regime can bring back into balance the normal micro flora and allow healing to occur.
There are two different issues a clinician must address in order to cure periodontal disease. The first obviously is the restoration of the normal micro flora, while the second is to restore the pocket to its normal state, at least to the extent possible. If the periodontal pocket is greater than 3 mm, then sulcular disinfection will not work because it only addresses one part of the problem—the microbes. This presents a major problem with periodontal pockets—even though you disinfect them, rogue microbes can easily migrate back into the deep protective pockets and start where they left off. One can continuously treat deep pockets and slow down the disease with a disinfection regime, but one will rarely restore the pockets to their pre-infection condition. Deep pockets provide too big a space for microbes and therefore require a different procedure in order to have some chance of success.
The laser curettage treatment described herein provides certain advantages that will advance the treatment and prognosis for patients suffering advanced stages of the disease—i.e., to the point where deep pockets have developed. Curettage is a procedure used by many periodontists, and consists of using small hand instruments to physically scrape away the diseased lining of epithelial cells from the bottom of the pocket. The idea is to scrape away the diseased tissue and, at the same time, cause a slight wound. The wound is key to decreasing pocket depth. And if there are insufficient interfering microbes the new gingival tissue will grow back higher on the tooth. Through multiple curettage treatments it is possible to eliminate the pocket entirely.
The curettage procedure described above has been used successfully on many patients. As described and disclosed below, the present invention dispenses with the use of hand instruments to destroy the diseased epithelial lining and, instead, uses a laser and a powerful disinfection regime. Specifically, while standard curettage comprises a physical scraping of tissue, the present invention achieves that result through the process of laser ablation of tissue combined with flooding the pocket with an anti-microbial solution. While lasers have been used in the treatment of periodontal disease, such treatments appear generally limited to photodynamic therapies, as disclosed, for example, in U.S. Patent Application Publication 2004/0259053 (Bekov et al.).
Recently, lasers have been used to treat periodontal disease by using a fiber-optic guide to direct laser energy into periodontal pockets to kill bacteria. One approach using this technique is disclosed, for example, in U.S. Pat. No. 6,663,386 (Moelsgaard). This less invasive and painful form of treatment does have its limitations, however, in that the laser is limited by the relative size of the guide and the ability to adequately control its direction. As such, areas needing treatment may not be adequately treated or can be missed entirely. What is needed is a method to improve upon the use of the laser treatment of periodontal disease for maximum coverage and disinfection of the treated area.